I. Field of the Invention
The present invention relates to surgical implants used in orthopedic surgery. More specifically, this invention relates to devices used to attach a tendon to a bone.
II. Related Art
A variety of different implantable devices have been employed to achieve tendon fixation to bone without the necessity of sutures or other secondary fixation intermediaries. The devices are generally used in the context of tendon repair or “tenodesis” surgery. In the case of the former, the device is used to reattach a tendon that has avulsed from its attachment. In the latter, the device is used to attach or fix a tendon in a given location that achieves a specific therapeutic end for the patient. For example, in the case of a “biceps tenodesis” procedure, most commonly the long head of the biceps tendon is fixed to bone in either a proximal location within the bicipital groove or in a more distal location in order to reduce or eliminate pain coming from a damaged portion of the tendon.
U.S. Pat. No 5,632,748 granted May 27, 1997 to Beck, Jr. et al discloses several different anchor devices. Each includes an anchor body and a separate threaded insertion member that is used either to wedge the anchor body against the wall of a tunnel formed in the bone, or to expand the anchor body against the wall of the tunnel. Implanting multiple parts in a confined area is inherently difficult, particularly when one must also employ tools to hold the anchor body in a position so the anchor body will not unduly pinch the tendon being anchored and, at the same time, tools to insert the insertion member into the tunnel adjacent the anchor body or into the anchor body itself. It is also difficult to achieve proper purchase of such parts in the tunnel to secure the tendon in place.
U.S. Pat. No. 8,048,158 to Mays et al likewise shows anchor devices including a ligament engagement member disposed in a bone tunnel with the ligament alongside the engagement member, and a locking member also disposed in the tunnel and engaging the ligament engagement member to wedge the ligament engagement member and ligament against the wall of the bone tunnel. The devices shown in Hays et al suffer from the same deficiencies as those shown in the aforementioned Beck, Jr. et al patent.
U.S. Pat. No. 8,512,805 to Baird discloses an anchor which also has two different pieces that are wedged against each other and the wall of a tunnel formed in the bone to secure a tendon in place. The Baird patent also discloses a tool for inserting the two implants which include a sharp tip inserted through the tendon to hold it in place as the two implants are pounded into the tunnel and wedged against each other. While this may assist in implanting the two pieces of the implant and holding the tendon in place, proper purchase and damage to the tendon remains an issue.